scholarly journals The Dynamics of Flow Discharge and Suspension Flow Discharge in Volcano Watershed with Agroforestry Land Cover

2021 ◽  
Vol 004 (02) ◽  
pp. 141-153
Author(s):  
La Hadini ◽  
Junun Sartohadi ◽  
Muhammad Setiawan ◽  
Djati Mardiatno
Keyword(s):  
Grain Size ◽  
Land Cover ◽  
Field Survey ◽  
Peak Flow ◽  
Clay Fraction ◽  
Suspension Flow ◽  
Time Interval ◽  
Rain Event ◽  
Flow Discharge ◽  
Rain Events

The suspension flow from the upper part of a volcano watershed, which has a very thick soil condition, is sensitive to landuse form. Agroforestry is the dominant landuse form in the volcanic landscape of Indonesia. There is a lack of detailed studies about suspension flow in the upper watershed where agroforestry is the land cover. This research, performed in agroforestry area, covered the correspondence between flow discharge and suspension flow discharge, the time lag of initial rain events and the formation of suspension flow; and the characteristics of the grain size of the suspensions during the flow. The suspension flow was measured at the outlet of a gully in key watershed areas, which yielded a total of 436 suspension data. The measurement analysis was conducted at every rain event in the field and in the laboratory. The crop characteristics in the rain catchment area were recorded in details during the field survey. The characteristics of the channels converging toward the gully system were observed during the field survey. There were three relationship patterns between the peak flow discharge and the peak suspension discharge, namely (1) the peak flow discharge corresponded to the peak suspension discharge, (2) the peak flow discharge preceded the peak suspension discharge, (3) the peak flow discharge occurred after the peak suspension discharge. The average time interval between the rain events and the occurrence of suspension flow was 17.7 minutes. The peak suspension content varied from 0.0016 g/L up to 4.71 g/L with an average of 1.03 g/L. The grain size of the suspension was dominated by 71-76% of clay fraction with an average of 73% at the rising phase and 68-71% of clay fraction with an average of 69% at the falling stage

scholarly journals The Run Off and Erosion on Eucalyptus Plantation Pt. Toba Pulp Lestari Aek Nauli Sector Simalungun District

2020 ◽  
Vol 8 (03) ◽  
pp. 285-288
Author(s):  
Tioner Purba ◽  
Sutrisno .
Keyword(s):  
Land Cover ◽  
Surface Flow ◽  
Rain Event ◽  
Vacant Land ◽  
Eucalyptus Plantation ◽  
Erosion Rates ◽  
Run Off ◽  
Measurement Results ◽  
Class 1 ◽  
Rain Events

This study aims to determine the amount of surface flow and the amount of erosion on vacant land and stands of Eucalyptus ages 1, 2, 3, 4 and 5 years in HTI PT. Toba Pulp Lestari, Aek Nauli sector. Observations dilakukan runoff and erosion measurements using runoff and erosion at each rain event system by observation of small plots measuring 22 x 4 m2 installed on each land cover  circumstances. The state of each plot research is in the area of ​​vacant land, stands of age class 1, 2, 3, 4 and 5 years, with 9% slope. The number of plots a total of 6 plots. And surface flow measurement is done by measuring the volume of water in the drum. Observations magnitude of runoff and sedimentation performed every 2 months during rain events. The results showed that the surface flow field measurement results showed variation and change in vacant land and a variety of ages eucalyptus. Lowest runoff occurs in the plot of land cover Eucalyptus age 1 year and highest in plots of land cover Eucalyptus age 2 years. The highest erosion rates occurred in plots of vacant land and is followed by a decrease in the Age of Eucalyptus 1,2,3,4 and 5 years.  

scholarly journals Impact of flow variability and sediment characteristics on channel width evolution

2018 ◽  
Vol 40 ◽  
pp. 05044
Author(s):  
Andrés Vargas-Luna ◽  
Alessandra Crosato ◽  
Protogene Byishimo ◽  
Wim Uijttewaal
Keyword(s):  
Grain Size ◽  
Peak Flow ◽  
River Channel ◽  
Channel Width ◽  
River Morphology ◽  
Channel Formation ◽  
Sediment Characteristics ◽  
Alluvial Rivers ◽  
Water Flows ◽  
Streamflow Variability

Alluvial rivers are shaped by sequences of water flows excavating their channels. Observations show that besides the magnitude, also the frequency and duration of streamflow oscillations might be important for the river channel formation. In addition, the river morphology appears influenced also by both size and degree of uniformity of the sediment. Nevertheless, many morphodynamic studies still represent the flow regime with a single value of the discharge, often corresponding to the bankfull condition, and the sediment with its median grain size. This work investigates the effects of streamflow variability and sediment characteristics on channel width formation, analysing the evolution of experimental streams with different sediments and discharge hydrographs. Results show that the formative condition of the channel width is not the geometric bankfull flow but a rather frequent peak flow. Remarkably different channel configurations arise from different sediment characteristics in the laboratory, where sediment non-uniformity produces more stable banks.

scholarly journals Continuous Monitoring of Turbidity and Conductivity in Wastewater Networks

2015 ◽  
Vol 28 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Thomas Bersinger ◽  
Isabelle Le Hécho ◽  
Gilles Bareille ◽  
Thierry Pigot ◽  
Alexandre Lecomte
Keyword(s):  
Total Nitrogen ◽  
Continuous Monitoring ◽  
Oxygen Demand ◽  
Rain Event ◽  
Aquatic Life ◽  
Pollutant Concentrations ◽  
Rain Events ◽  
The One ◽  
Continuous Estimation ◽  
The Impact

Continuous monitoring of the sanitation network of the urban catchment of Pau (southwest France) has been performed since March 2012 using rain gauges, flowmeters, as well as turbidity and conductivity probes. Good correlations were obtained between turbidity, total suspended solids (TSS) and chemical oxygen demand (COD) on the one hand, and conductivity and total nitrogen on the other hand. This allowed an instantaneous and continuous estimation of pollutant concentrations and fluxes since that date. In the present paper we focused on the results of October 2012, which was characterized by alternating periods of dry and rainy events. Turbidity and conductivity raw data show different trends during the study period depending on the parameter and the rain events. A turbidity peak is observed at the beginning of each rain event but its amplitude varies with the intensity of the rain and the length of the preceding dry weather period. Conversely, conductivity decrease during each rain event implying, that rain water acts as a dilution factor. The behaviour of COD and total nitrogen differ markedly due to their partitioning between the dissolved (total nitrogen) and particulate phases (COD). Daily pollutant fluxes allow a global comprehension and monitoring of the sewer system. Important COD fluxes during a rain event preceded by a long dry weather period highlight the importance of erosion of sedimentary deposits in the sewerage network. During these events, important fluxes are discharged into receiving water leading to the question of the impact on aquatic life. Generally, these results highlight the potential of online monitoring to better understand the behaviour of the sewer network on long or short time scales. This could be a useful tool to manage wastewater treatment.

scholarly journals Scale invariant events and dry spells for medium-resolution local rain data

2014 ◽  
Vol 21 (2) ◽  
pp. 555-567 ◽  
Author(s):  
A. Deluca ◽  
Á. Corral
Keyword(s):  
Finite Size ◽  
Mediterranean Coast ◽  
Rain Event ◽  
Scale Invariant ◽  
Scaling Properties ◽  
Medium Resolution ◽  
Dry Spells ◽  
Dry Spell ◽  
Rain Events ◽  
Rain Data

Abstract. We analyze distributions of rain-event sizes, rain-event durations, and dry-spell durations for data obtained from a network of 20 rain gauges scattered in a region of the northwestern Mediterranean coast. While power-law distributions model the dry-spell durations with a common exponent 1.50 ± 0.05, density analysis is inconclusive for event sizes and event durations, due to finite size effects. However, we present alternative evidence of the existence of scale invariance in these distributions by means of different data collapses of the distributions. These results demonstrate that scaling properties of rain events and dry spells can also be observed for medium-resolution rain data.

scholarly journals Export of <sup>134</sup>Cs and <sup>137</sup>Cs in the Fukushima river systems at heavy rains by Typhoon Roke in September 2011

2013 ◽  
Vol 10 (2) ◽  
pp. 2767-2790 ◽  
Author(s):  
S. Nagao ◽  
M. Kanamori ◽  
S. Ochiai ◽  
S. Tomihara ◽  
K. Fukushi ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Heavy Rain ◽  
Rain Event ◽  
Normal Flow ◽  
Flow Conditions ◽  
Pulse Input ◽  
Heavy Rain Event ◽  
Coastal Marine ◽  
Rain Events ◽  
Heavy Rains

Abstract. Effects of a heavy rain event on radiocesium export were studied at stations on the Natsui River and the Same River in Fukushima Prefecture, Japan after Typhoon Roke during 21–22 September 2011, six months after the Fukushima Daiichi Nuclear Power Plant accident. Radioactivity of 134Cs and 137Cs in river waters was 0.011–0.098 Bq L−1 at normal flow conditions during July–September in 2011, but it increased to 0.85 Bq L−1 in high flow conditions by heavy rains occurring with the typhoon. The particulate fractions of 134Cs and 137Cs were 21–56% in the normal flow condition, but were close to 100% after the typhoon. These results indicate that the pulse input of radiocesium associated with suspended particles from land to coastal ocean occurred by the heavy rain event. Export flux of 134Cs and 137Cs by the heavy rain accounts for 30–50% of annual radiocesium flux in 2011. Results show that rain events are one factor controlling the transport and dispersion of radiocesium in river watersheds and coastal marine environments.

Impact of a severe rain event on C- and N-DBP precursor removal using IEX

2018 ◽  
Vol 18 (6) ◽  
pp. 2092-2099
Author(s):  
K. Doederer ◽  
Z. Ilieva ◽  
J. Keller
Keyword(s):  
Ion Exchange ◽  
Heavy Rain ◽  
Health Concern ◽  
Rain Event ◽  
Heavy Rain Event ◽  
Removal Capacity ◽  
C And N ◽  
Pre Treatment ◽  
Rain Events ◽  
Magnetic Ion

Abstract During disinfection, dissolved organic matter (DOM) is the major precursor to form disinfection by-products (DBPs), which may be of potential human health concern. Previous research focused on waters of continental climates and less on subtropical environments. However, water sources in subtropical climates are regularly impacted by major rain events during the summer months. This study evaluated the C- and N-DBP precursor removal capacity of two conventional ion exchange (IEX) resins and one magnetic ion exchange (MIEX) resin with a raw water at normal conditions and impacted by a heavy rain event. The rain event introduced 3 mg C/L total organic carbon (TOC) comprised mainly of low to medium molecular weight organics. All three resins were able to remove TOC and DBP precursors (&gt;66%) but being less efficient in reducing turbidity (3–48%) and colour (9–24%). The resin with the smallest bead size was affected the most by the increased medium MW DOM loading resulting in DOM and C-DBP precursor removal performance losses of 10% and 22%. When applied as a pre-treatment for coagulation, MIEX was more efficient in DBP precursor control than coagulation in addressing the additional organic and DBP precursor loading after a heavy rain event.

Aminophylline Therapy Does Not Improve Outcome and Increases Adverse Effects in Children Hospitalized With Acute Asthmatic Exacerbations

PEDIATRICS ◽  
1994 ◽  
Vol 93 (2) ◽  
pp. 205-210
Author(s):  
Raphael E. Strauss ◽  
David L. Wertheim ◽  
Vincent R. Bonagura ◽  
David J. Valacer
Keyword(s):  
New York ◽  
Adverse Effects ◽  
Hospital Admissions ◽  
Peak Flow ◽  
Controlled Trial ◽  
Tertiary Care ◽  
Time Interval ◽  
Double Blind ◽  
Flow Rates ◽  
Duration Of Hospitalization

Objective. To evaluate the effects of aminophylline (Am) in children hospitalized with asthma. Methods. Prospective, randomized, double-blind, placebo-controlled trial. Subjects were children between the ages of 5 and 18 years admitted for asthma exacerbation to either a tertiary care children's hospital or an innercity general hospital in New York. Exclusion criteria were admission to the intensive care unit, initial theophylline level &gt; 5 µg/dL, or the presence of other systemic disorders. All patients received nebulized albuterol therapy and intravenous glucocorticosteroids in standardized doses. Thirty-one patients were randomized to receive either an Am bolus followed by continuous Am infusion or placebo (P) bolus and infusion. The outcome variables were: duration of hospitalization, percent of predicted peak expiratory flow rates recorded at 12-hour intervals, number of albuterol treatments required, and adverse effects. Results. There were no significant differences at study entry in age, sex, race, number of previous hospital admissions, prior medications used, clinical symptom scores, or initial peak flow rates for the two groups. For 26 patients who completed this study, 15 patients in the P group were hospitalized for a mean duration of 2.33 ± 1.3 days, whereas 11 patients in the Am group required 2.58 ± 1.5 days. There were no significant differences between the two groups for hospital days, peak flow rates at any time interval, or amount of albuterol therapy required (P &gt; .2). In the Am group, 6 of the 14 patients who entered the study experienced significant adverse effects consisting of nausea, emesis, headache, abdominal pain, and palpitations. Only 1 of 17 patients in the P group had an adverse effect (P &lt;. 05). Conclusions. There is no benefit and considerable risk of adverse effects associated with the use of Am in hospitalized asthmatic children.

scholarly journals Relevant parameters for characterizing mountain rivers: a review

RBRH ◽  
2019 ◽  
Vol 24 ◽  
Author(s):  
Maurício Andrades Paixão ◽  
Masato Kobiyama
Keyword(s):  
Power Generation ◽  
Grain Size ◽  
Water Resources ◽  
Fluvial Geomorphology ◽  
Field Survey ◽  
Hydroelectric Power ◽  
Mountain Rivers ◽  
Fluvial Dynamics ◽  
Sporting Activities ◽  
Hydroelectric Power Generation

ABSTRACT Mountain rivers are situated in a large portion of the terrestrial surface, especially in headwaters regions, and have been used for various purposes such as recreation, sporting activities, water resources and hydroelectric power generation. However, hydrogeomorphic characteristics of mountain rivers are not fully understood. In this context, the present paper aimed to identify relevant parameters for characterizing rivers in these environments based on bibliographical review. It was identified which parameters have been used and how they have been used to characterize mountain rivers in distinct classifications. The most cited parameters were channel gradient, relation between river width and depth, entrenchment ratio, discharge, sediment transport and grain-size distribution. Also, the current situation related to researches in fluvial geomorphology in mountain rivers in Brazil was evaluated, and the strong need of field survey as basis for the best understanding of mountain fluvial dynamics and characterization was verified.

scholarly journals Rain event properties at the source of the Blue Nile River

2011 ◽  
Vol 15 (3) ◽  
pp. 1023-1034 ◽  
Author(s):  
A. T. Haile ◽  
T. H. M. Rientjes ◽  
E. Habib ◽  
V. Jetten ◽  
M. Gebremichael
Keyword(s):  
Rain Rate ◽  
Rainfall Data ◽  
Nile River ◽  
Rain Event ◽  
Spatial And Temporal Patterns ◽  
Mountain Area ◽  
Event Duration ◽  
Blue Nile ◽  
Event Time ◽  
Rain Events

Abstract. In the present study, spatial and temporal patterns of rain event properties are analysed. These event properties are rain event depth, event duration, mean event rain rate, peak rain rate and the time span between two consecutive rain events which is referred to as inter-event time (IET). In addition, we assessed how rain event properties change when the period over which rainfall data is aggregated changes from 1 to 6 min and when the minimum inter-event time (MIT) changes from 30 min to 8 h. Rainfall data is obtained from a field campaign in two wet seasons of June–August (JJA) of 2007 and 2008 in Gilgel Abbay watershed that is situated at the source basin of the Upper Blue Nile River in Ethiopia. The rainfall data was automatically recorded at eight stations. The results revealed that rain event depth is more related to peak rain rate than to event duration. At the start and towards the end of the wet season, the rain events have larger depth with longer duration and longer IET than those in mid-season. Event rain rate and IET are strongly related to terrain elevation. Sekela which is on a mountain area has the shortest IET while Bahir Dar which is at the south shore of Lake Tana has the longest IET. The period over which rainfall data is aggregated significantly affected the values of rain event properties that are estimated using relatively small value (30 min) of MIT but its effect diminished when the MIT is increased to 8 h. It is shown that increasing the value of MIT has the largest effect on rain event properties of mountain stations that are characterised by high rainfall intermittency.

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